Never mind. I found another post that references Polygon’s list of exchanges, and they do seem to match.
https://api.polygon.io/v1/meta/exchanges?apiKey=[your own free api key]
[
{
"id": 0,
"type": "TRF",
"market": "equities",
"mic": "TFF",
"name": "Multiple",
"tape": "-"
},
{
"id": 1,
"type": "exchange",
"market": "equities",
"mic": "XASE",
"name": "NYSE American (AMEX)",
"tape": "A",
"code": "AMX"
},
{
"id": 2,
"type": "exchange",
"market": "equities",
"mic": "XNAS",
"name": "NASDAQ OMX BX",
"tape": "B",
"code": "NSD"
},
{
"id": 3,
"type": "TRF",
"market": "equities",
"name": "National Stock Exchange",
"mic": "XCIS",
"tape": "C"
},
{
"id": 4,
"type": "TRF",
"market": "equities",
"mic": "FINR",
"name": "FINRA",
"tape": "D"
},
{
"id": 5,
"type": "TRF",
"market": "equities",
"mic": "CQS",
"name": "Consolidated Quote System",
"tape": "E"
},
{
"id": 6,
"type": "TRF",
"market": "equities",
"mic": "XISX",
"name": "International Securities Exchange",
"tape": "I",
"code": "IOE"
},
{
"id": 7,
"type": "exchange",
"market": "equities",
"mic": "EDGA",
"name": "Cboe EDGA",
"tape": "J",
"code": "XCBO"
},
{
"id": 8,
"type": "exchange",
"market": "equities",
"mic": "EDGX",
"name": "Cboe EDGX",
"tape": "K",
"code": "EDGX"
},
{
"id": 9,
"type": "exchange",
"market": "equities",
"mic": "XCHI",
"name": "Chicago Stock Exchange, Inc",
"tape": "M"
},
{
"id": 10,
"type": "exchange",
"market": "equities",
"mic": "XNYS",
"name": "New York Stock Exchange",
"tape": "N",
"code": "NYE"
},
{
"id": 11,
"type": "exchange",
"market": "equities",
"mic": "ARCX",
"name": "NYSE Arca",
"tape": "P",
"code": "ARCA"
},
{
"id": 12,
"type": "exchange",
"market": "equities",
"mic": "XNGS",
"name": "Nasdaq",
"tape": "T",
"code": "NSD"
},
{
"id": 13,
"type": "TRF",
"market": "equities",
"mic": "CTS",
"name": "Consolidated Tape System",
"tape": "S"
},
{
"id": 14,
"type": "TRF",
"market": "equities",
"mic": "OOTC",
"name": "OTC Bulletin Board",
"tape": "U"
},
{
"id": 141,
"type": "TRF",
"market": "equities",
"mic": "XOTC",
"name": "OTC Bulletin Board",
"tape": "U"
},
{
"id": 142,
"type": "TRF",
"market": "equities",
"mic": "PSGM",
"name": "OTC Bulletin Board",
"tape": "U",
"code": "GREY"
},
{
"id": 143,
"type": "TRF",
"market": "equities",
"mic": "PINX",
"name": "OTC Bulletin Board",
"tape": "U",
"code": "OTO"
},
{
"id": 144,
"type": "TRF",
"market": "equities",
"mic": "OTCB",
"name": "OTC Bulletin Board",
"tape": "U",
"code": "OTCQB"
},
{
"id": 145,
"type": "TRF",
"market": "equities",
"mic": "OTCQ",
"name": "OTC Bulletin Board",
"tape": "U",
"code": "OTCQX"
},
{
"id": 15,
"type": "exchange",
"market": "equities",
"mic": "IEXG",
"name": "IEX",
"tape": "V",
"code": "IEXG"
},
{
"id": 16,
"type": "TRF",
"market": "equities",
"mic": "XCBO",
"name": "Chicago Board Options Exchange",
"tape": "W",
"code": "CBO"
},
{
"id": 17,
"type": "exchange",
"market": "equities",
"mic": "PHLX",
"name": "Nasdaq PSX",
"tape": "X"
},
{
"id": 18,
"type": "exchange",
"market": "equities",
"mic": "BATY",
"name": "Cboe BYX",
"tape": "Y",
"code": "BATS"
},
{
"id": 19,
"type": "exchange",
"market": "equities",
"mic": "BATS",
"name": "Cboe BZX",
"tape": "Z",
"code": "BATS"
},
{
"id": 33,
"type": "exchange",
"market": "equities",
"mic": "XBOS",
"name": "NASDAQ BX Options/ETF",
"tape": "B"
},
{
"id": 36,
"type": "exchange",
"market": "index",
"name": "CME S&P Complete Indices",
"code": "SPIC"
},
{
"id": 37,
"type": "exchange",
"market": "index",
"name": "Russell Tick Indices",
"code": "RUS"
},
{
"id": 38,
"type": "exchange",
"market": "index",
"name": "CSMI Indices Exchange",
"code": "MDX"
},
{
"id": 39,
"type": "exchange",
"market": "index",
"name": "CME S&P Base Indices",
"code": "SPIB"
},
{
"id": 40,
"type": "exchange",
"market": "index",
"name": "Dow Jones Indexes",
"code": "DJI"
},
{
"id": 20,
"type": "banking",
"market": "currencies",
"name": "Currency Banks 1"
},
{
"id": 44,
"type": "banking",
"market": "currencies",
"name": "Currency Banks 2"
},
{
"id": 60,
"type": "banking",
"market": "currencies",
"name": "Currency Banks 3"
}
]