I only selected county-to-county $100M+ AGI(adjusted gross income) that were out-of-state or out of Metro for multi-state metro areas. This is for 2022-2023(latest data available online), this is not complete, just the data I have calculated up to this point.
3 of these county-to-country pairings have an average return that is $700,000--the next two as far as average amts look like Manhattan-Palm Beach and SF-Austin, the very high average return from Contra Costa, CA to Harris, TX was Chevron workers before they moved their HQ to Houston---otherwise it looks like a lot of money flows to Florida, Maricopa AZ and Clark, NV
Total
Adjusted
Gross
Income
Leaving-----Average
County------Return----County of Income Origin & Destination County
$640.3M---$282,833--New York, NY to Los Angeles, CA
$547.4M---$215,805--Los Angeles, CA to New York, NY
$525.4M---$711,064--Cook, IL to Miami-Dade, FL
$521.4M---$87,206---Los Angeles, CA to Clark, NV
$516.7M---$357,633--New York, NY to Miami-Dade, FL
$424.3M---$578,148--New York, NY to Palm Beach, FL
$420.6M---$200,319--San Francisco, CA to Los Angeles, CA
$362.1M---$219,058--San Francisco, CA to New York, NY
$342.0M---$233,941--Santa Clara, CA to King, WA
$301.3M---$200,625--King, WA to Maricopa, AZ
$299.3M---$155,654--Cook, IL to New York, NY
$297.2M---$126,295--Los Angeles to Santa Clara, CA
$295.1M---$135,958--Santa Clara, CA to Los Angeles, CA
$289.2M---$122,394--Los Angeles, CA to King, WA
$282.2M---$79,246---Los Angeles, CA to Maricopa, AZ
$279.8M---$318,759--New York, NY to Cook, IL
$271.7M---$223,817--King, WA to Santa Clara, CA
$264.2M---$166,813--Santa Clara, CA to San Diego, CA
$261.5M---$712,615--Cook, IL to Collier, FL
$244.5M---$262,523--Cook, IL to Palm Beach, FL
$239.3M---$228,154--Los Angeles, CA to Miami-Dade, FL
$236.4M---$98,126---San Diego, CA to Maricopa, AZ
$235.9M---$293,407--New York, NY to San Francisco, CA
$233.7M---$127,247--Orange, CA to Clark, NV
$230.2M---$122,661--Los Angeles, CA to San Francisco, CA
$228.9M---$127,267--King, WA to Los Angeles, CA
$227.9M---$107,619--Alameda, CA to Los Angeles, CA
$226.6M---$114,334--Cook, IL to Los Angeles, CA
$223.8M---$131,830--Cook, IL to Maricopa, AZ
$208.8M---195,874---Cook, IL to Dallas, TX
$197.4M---$106,295--Orange, CA to Maricopa, AZ
$187.5M---$150,559--Suffolk, MA to New York, NY
$180.8M---$280,891--Santa Clara, CA to Travis, TX
$180.1M---$194,366--San Francisco, CA to San Diego, CA
$174.7M---$80,110---Maricopa, AZ to Los Angeles, CA
$171.7M---$194,055--San Francisco, CA to Kings, NY
$167.3M---$110,448--Santa Clara, CA to Sacramento, CA
$166.2M---$91,943---San Diego, CA to Clark, NV
$166.1M---$103,702--Los Angeles, CA to Kings, NY
$160.2M---$134,633--San Diego, CA to Santa Clara, CA
$160.0M---$143,903--King, WA to San Diego, CA
$153.0M---$166,684--King, WA to New York, NY
$151.5M---$95,163---Alameda, CA to Sacramento, CA
$150.6M---$124,478--Washington, DC to New York, NY
$150.3M---$95,795---Los Angeles, CA to Cook, IL
$146.6M---$492,016--San Francisco, CA to Travis, TX
$143.9M---$171,564--Santa Clara, CA to New York, NY
$143.2M---$311,982--New York, NY to San Diego, CA
$142.5M---$125,562--Los Angeles, CA to Tarrant, TX
$142.2M---$204,445--San Francisco, CA to King, WA
$141.6M---$179,355--King, WA to San Francisco, CA
$139.5M---$190,844--New York, NY to Suffolk, MA
$138.8M---$136,251--Alameda, CA to San Diego, CA
$137.3M---$227,354--Hennepin, MN to Maricopa, AZ
$136.5M---$80,050---Maricopa, AZ to San Diego, CA
$133.9M---$223,153--San Mateo, CA to San Diego, CA
$131.4M---$200,003--King, WA to Travis, TX
$129.4M---$117,916--Los Angeles, CA to Dallas, TX
$128.2M---$142,521--San Mateo, CA to Los Angeles, CA
$125.4M---$171,784--King, WA to Orange, CA
$124.9M---$262,523--Cook, IL to Broward, FL
$124.3M---$425,684--Contra Costa, CA to Harris, TX
$123.7M---$75,154---Los Angeles, CA to Harris, TX
$123.0M---$145,439--Alameda, CA to King, WA
$122.7M---$194,219--Santa Clara, CA to Clark, NV
$121.7M---$100,415--Middlesex, MA to New York, NY
$121.7M---$129,944--Orange, CA to King, WA
$120.7M---$126,558--Cook, IL to King, WA
$120.6M---$160,916--New York, NY to Washington, DC
$120.4M---$165,263--Alameda, CA to Orange, CA
$118.6M---$217,710--Dallas, TX to New York, NY
$118.4M---$176,461--Dallas, TX to Cook, IL
$117.2M---$182,945--New York, NY to Middlesex, MA
$116.3M---$174,214--Santa Clara, CA to Maricopa, AZ
$115.8M---$271,243--San Francisco, CA to Cook, IL
$114.1M---$169,644--Santa Clara, CA to Placer, CA
$111.4M---$753,297--Norfolk, MA to Palm Beach, FL
$110.0M---$198,019--San Francisco, CA to Orange, CA
$109.7M---$97,266---San Diego, CA to King, WA
$109.4M---$168,318--Contra Costa, CA to San Diego, CA
$109.3M---$124,685--New York, NY to Philadelphia, PA
$107.4B---$190,242--Travis, TX to King, WA
$107.5M---$292,203--Cook, IL to Lee, FL
$105.0M---$114,326--Orange, CA to Santa Clara, CA
$102.7M---$133,975--Cook, IL to Travis, TX
$101.6M---$137,335--Dallas, TX to Los Angeles, CA
Denver, CO, Harris, TX & Fulton, GA had no out-of-state, county-to-county outflow that was $100M+
https://www.irs.gov/statistics/soi-tax-stats-migration-data-2022-2023