diff --git a/internal/getproviders/memoize_source.go b/internal/getproviders/memoize_source.go
new file mode 100644
index 0000000000..19e08d58c0
--- /dev/null
+++ b/internal/getproviders/memoize_source.go
@@ -0,0 +1,96 @@
+package getproviders
+
+import (
+	"sync"
+
+	"github.com/hashicorp/terraform/addrs"
+)
+
+// MemoizeSource is a Source that wraps another Source and remembers its
+// results so that they can be returned more quickly on future calls to the
+// same object.
+//
+// Each MemoizeSource maintains a cache of response it has seen as part of its
+// body. All responses are retained for the remaining lifetime of the object.
+// Errors from the underlying source are also cached, and so subsequent calls
+// with the same arguments will always produce the same errors.
+//
+// A MemoizeSource can be called concurrently, with incoming requests processed
+// sequentially.
+type MemoizeSource struct {
+	underlying        Source
+	availableVersions map[addrs.Provider]memoizeAvailableVersionsRet
+	packageMetas      map[memoizePackageMetaCall]memoizePackageMetaRet
+	mu                sync.Mutex
+}
+
+type memoizeAvailableVersionsRet struct {
+	VersionList VersionList
+	Err         error
+}
+
+type memoizePackageMetaCall struct {
+	Provider addrs.Provider
+	Version  Version
+	Target   Platform
+}
+
+type memoizePackageMetaRet struct {
+	PackageMeta PackageMeta
+	Err         error
+}
+
+var _ Source = (*MemoizeSource)(nil)
+
+// NewMemoizeSource constructs and returns a new MemoizeSource that wraps
+// the given underlying source and memoizes its results.
+func NewMemoizeSource(underlying Source) *MemoizeSource {
+	return &MemoizeSource{
+		underlying:        underlying,
+		availableVersions: make(map[addrs.Provider]memoizeAvailableVersionsRet),
+		packageMetas:      make(map[memoizePackageMetaCall]memoizePackageMetaRet),
+	}
+}
+
+// AvailableVersions requests the available versions from the underlying source
+// and caches them before returning them, or on subsequent calls returns the
+// result directly from the cache.
+func (s *MemoizeSource) AvailableVersions(provider addrs.Provider) (VersionList, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if existing, exists := s.availableVersions[provider]; exists {
+		return existing.VersionList, existing.Err
+	}
+
+	ret, err := s.underlying.AvailableVersions(provider)
+	s.availableVersions[provider] = memoizeAvailableVersionsRet{
+		VersionList: ret,
+		Err:         err,
+	}
+	return ret, err
+}
+
+// PackageMeta requests package metadata from the underlying source and caches
+// the result before returning it, or on subsequent calls returns the result
+// directly from the cache.
+func (s *MemoizeSource) PackageMeta(provider addrs.Provider, version Version, target Platform) (PackageMeta, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	key := memoizePackageMetaCall{
+		Provider: provider,
+		Version:  version,
+		Target:   target,
+	}
+	if existing, exists := s.packageMetas[key]; exists {
+		return existing.PackageMeta, existing.Err
+	}
+
+	ret, err := s.underlying.PackageMeta(provider, version, target)
+	s.packageMetas[key] = memoizePackageMetaRet{
+		PackageMeta: ret,
+		Err:         err,
+	}
+	return ret, err
+}