Symbols / MORTGAGE_15Y

MORTGAGE_15Y

US 15-Year Fixed Mortgage Rate

Freddie Mac Primary Mortgage Market Survey, 15-year fixed rate.

Reference Active

Country

USD

Frequency

weekly

Update cadence

What is US 15-Year Fixed Mortgage Rate (MORTGAGE_15Y)?

US 15-Year Fixed Mortgage Rate is a reference rate — a standardized benchmark published by an official body, used as the basis for pricing financial contracts, loans, and derivatives. Reference rates provide a transparent, manipulation-resistant alternative to panel-based rates.

Reference rates are embedded in loan agreements, bond indentures, and derivatives as the floating-rate component. Regulators and central banks have actively promoted official reference rates as replacements for rates that were subject to manipulation, improving the integrity of financial benchmarks globally.

Published by central banks or regulators
Based on actual transaction data
Used in ISDA FX and rates definitions
Key input for hedge accounting

Uses and Related Industries

Primary Industries

Commercial Banking: Loan agreement base rate for floating-rate commercial credit facilities.

Derivatives Market: ISDA-defined fallback rate in FX and rates derivative contracts.

Structured Finance: ABS, RMBS, and CLO coupon reset benchmark in post-LIBOR transition landscape.

Risk Management: Hedge accounting designation and effectiveness testing under IFRS 9 / ASC 815.

Regulatory Reporting: Mandated reference rate for regulatory capital calculations and stress testing.

Specific Applications

ISDA FX and rates definitions fallback rate implementation
Hedge accounting reference rate under IFRS 9 and US GAAP
Loan agreement base rate substitution post-LIBOR transition
Overnight Index Swap (OIS) curve construction
Regulatory stress testing and internal model validation

API Usage Examples for MORTGAGE_15Y

Click each endpoint to see the request URL, parameters, and a sample response.

API Request

https://interestratesapi.com/api/v1/latest?api_key=YOUR_API_KEY&symbols=MORTGAGE_15Y

Request Parameters

Parameter	Required	Description
api_key	required	Your API key.
symbols	required	Comma-separated symbol codes. E.g. MORTGAGE_15Y

Sample Response

{
    "success": true,
    "date": "2026-05-26",
    "rates": {
        "MORTGAGE_15Y": 4.25
    },
    "dates": {
        "MORTGAGE_15Y": "2026-05-26"
    }
}

API Request

https://interestratesapi.com/api/v1/historical?api_key=YOUR_API_KEY&symbols=MORTGAGE_15Y&date=2026-05-26

Request Parameters

Parameter	Required	Description
api_key	required	Your API key.
symbols	required	Symbol code(s). E.g. MORTGAGE_15Y
date	required	Date in YYYY-MM-DD format.

Sample Response

{
    "success": true,
    "historical": true,
    "date": "2026-05-26",
    "rates": {
        "MORTGAGE_15Y": 4.25
    }
}

API Request

https://interestratesapi.com/api/v1/timeseries?api_key=YOUR_API_KEY&symbols=MORTGAGE_15Y&start_date=2026-05-03&end_date=2026-06-02

Request Parameters

Parameter	Required	Description
api_key	required	Your API key.
symbols	required	Symbol code(s). E.g. MORTGAGE_15Y
start_date	required	Start date (YYYY-MM-DD).
end_date	required	End date (YYYY-MM-DD).

Sample Response

{
    "success": true,
    "symbols": [
        "MORTGAGE_15Y"
    ],
    "rates": {
        "2026-05-03": {
            "MORTGAGE_15Y": 4.25
        },
        "2026-06-02": {
            "MORTGAGE_15Y": 4.25
        }
    }
}

API Request

https://interestratesapi.com/api/v1/fluctuation?api_key=YOUR_API_KEY&symbols=MORTGAGE_15Y&start_date=2026-05-03&end_date=2026-06-02

Request Parameters

Parameter	Required	Description
api_key	required	Your API key.
symbols	required	Symbol code(s). E.g. MORTGAGE_15Y
start_date	required	Start date (YYYY-MM-DD).
end_date	required	End date (YYYY-MM-DD).

Sample Response

{
    "success": true,
    "fluctuation": {
        "MORTGAGE_15Y": {
            "start_rate": 4.25,
            "end_rate": 4.37,
            "change": 0.12,
            "change_pct": 2.8235
        }
    }
}

API Request

https://interestratesapi.com/api/v1/ohlc?api_key=YOUR_API_KEY&symbols=MORTGAGE_15Y&start=2026-05-03&end=2026-06-02&period=monthly

Request Parameters

Parameter	Required	Description
api_key	required	Your API key.
symbols	required	Symbol code. E.g. MORTGAGE_15Y
start	required	Start date (YYYY-MM-DD).
end	optional	End date (YYYY-MM-DD). Defaults to today.
period	optional	Grouping: monthly (default), weekly, quarterly.

Sample Response

{
    "success": true,
    "symbol": "MORTGAGE_15Y",
    "period": "monthly",
    "ohlc": [
        {
            "period": "2026-05",
            "open": 4.25,
            "high": 4.5,
            "low": 4.15,
            "close": 4.37,
            "data_points": 21
        }
    ]
}

API Request

https://interestratesapi.com/api/v1/convert?api_key=YOUR_API_KEY&from=MORTGAGE_15Y&to=FED_FUNDS&amount=1

Request Parameters

Parameter	Required	Description
api_key	required	Your API key.
from	required	Source symbol. E.g. MORTGAGE_15Y
to	required	Target symbol. E.g. FED_FUNDS
amount	required	Amount to convert.
term_months	optional	Term in months for interest calculation (default 12).

Sample Response

{
    "success": true,
    "from": "MORTGAGE_15Y",
    "to": "FED_FUNDS",
    "amount": 1,
    "result": 0.981524
}

Replace YOUR_API_KEY with your key Get a free API key →

Factors Influencing MORTGAGE_15Y

Market Factors

Underlying overnight interbank lending conditions
Central bank policy rate and corridor floor/ceiling
Short-term money market supply and demand
Credit conditions in the broader financial system

Technical Factors

Transaction volume and liquidity in the reference rate calculation
Methodology changes in rate computation (e.g., trimmed mean)
Compounding convention (overnight vs. term)
Spread adjustments applied during IBOR fallback transition

External Factors

Regulatory framework and oversight body decisions
IBOR reform implementation milestones and cessation dates
Central bank communication and forward guidance
Market structure changes in overnight repo and lending

Other rates from US

FED_FUNDS

Federal Funds Effective Rate

FED_FUNDS_DAILY

Federal Funds Effective Rate (Daily)

SOFR

Secured Overnight Financing Rate

US_TREASURY_1M

US Treasury Yield 1-Month

US_TREASURY_3M

US Treasury Yield 3-Month

US_TREASURY_6M

US Treasury Yield 6-Month

Other Reference rates

PRIME_RATE

US Prime Rate

MORTGAGE_30Y

US 30-Year Fixed Mortgage Rate

US_BREAKEVEN_10Y

US 10-Year Breakeven Inflation Rate

US_BREAKEVEN_5Y

US 5-Year Breakeven Inflation Rate

US_YIELD_SPREAD_10Y2Y

US Treasury Yield Spread 10Y-2Y

US_YIELD_SPREAD_10Y3M

US Treasury Yield Spread 10Y-3M

Symbol Details

Symbol: MORTGAGE_15Y
Category: Reference
Country: US
Currency: USD
Provider: fred
Frequency: weekly
Series ID: MORTGAGE15US
Unit: percent

Access MORTGAGE_15Y via REST API

Get live and historical US 15-Year Fixed Mortgage Rate data in JSON format. One API, 50+ countries, normalized.

Get Free API Key View API Docs

GET /api/latest?symbols=MORTGAGE_15Y

Back to all symbols